Differential Diagnosis for Abdominal Pain

The patient presents with mid upper abdominal pain radiating to the right flank, exacerbated by certain foods, particularly fatty meals, suggesting a possible correlation with dietary intake. Given her symptoms and the results of her extensive workup, the following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Biliary Dyskinesia: This condition is characterized by a gallbladder that doesn't empty properly, which can cause abdominal pain, especially after eating fatty foods. The slightly reduced gallbladder ejection fraction on the HIDA scan supports this diagnosis, as it indicates impaired gallbladder function.

• Other Likely Diagnoses

  • Irritable Bowel Syndrome (IBS): Although the patient's symptoms are more suggestive of a biliary or pancreatic issue due to the postprandial worsening and radiation to the flank, IBS could still be considered, especially if the patient has other undiagnosed gastrointestinal symptoms.
  • Chronic Pancreatitis: This condition can cause recurrent abdominal pain that radiates to the back and can be exacerbated by eating. The lack of other symptoms like nausea, vomiting, or changes in bowel habits does not rule out this diagnosis, as chronic pancreatitis can have a varied presentation.
  • Gastroesophageal Reflux Disease (GERD): Although less likely given the radiation of pain to the flank, GERD can cause epigastric pain that worsens after eating. However, the absence of typical GERD symptoms like heartburn or regurgitation makes this less likely.

• Do Not Miss Diagnoses

  • Gallbladder Cancer: Although rare, gallbladder cancer can present with nonspecific symptoms similar to those of biliary dyskinesia or cholecystitis. The patient's concern about gallbladder pathology and the presence of persistent symptoms despite negative initial workup warrant consideration of this diagnosis.
  • Pancreatic Cancer: Similar to gallbladder cancer, pancreatic cancer is rare but can present with vague abdominal pain that radiates to the back. The absence of weight loss, jaundice, or other alarming symptoms does not exclude this diagnosis.
  • Peptic Ulcer Disease: A peptic ulcer can cause epigastric pain that worsens with eating, and while less likely given the flank radiation, it is a condition that should not be missed due to its potential for complications like bleeding or perforation.

• Rare Diagnoses

  • Sphincter of Oddi Dysfunction: This condition involves abnormal function of the sphincter of Oddi, which controls the flow of bile and pancreatic juices into the small intestine. It can cause biliary-type pain and can be considered in patients with persistent symptoms and negative workup for other biliary and pancreatic diseases.
  • Celiac Disease: Although primarily known for causing malabsorption and changes in bowel habits, celiac disease can also cause abdominal pain. The patient's symptoms could potentially be related to celiac disease, especially if specific food triggers are identified.
  • Abdominal Migraine: This is a rare condition that can cause recurrent episodes of severe abdominal pain, often accompanied by other migraine symptoms. It is more common in children but can occur in adults, and its consideration is based on the exclusion of other diagnoses and the presence of migraine-like features.